In the downhole industry, whipstocks or other diverting tools are often run into a borehole hanging from the end of a milling or drilling bottom hole assembly (BHA) so that the whipstock may be positioned and anchored and then the BHA actuated to create the desired borehole exit (and potentially lateral borehole) in a single run. This methodology is well known to the industry. The whipstock is conventionally attached to the BHA by a configuration colloquially known as a lug. The lug generally extends through a portion of the whipstock and into connection with the BHA. The connection with the BHA generally requires a specially created interface such as a milled slot.
During use, the whipstock is landed and then torque, slack weight or both are used to shear the lug thereby disconnecting the BHA from the whipstock and the milling or drilling operation can begin.
Systems as described work well for their intended purposes but research effort has been applied to enhancing the connection between the whipstock and BHA during running to discourage or prevent premature separation and at the same time to reduce required input to cause the separation at the appropriate time. While alternatives have been proposed, they have not satiated the need and hence the art still pines for new solutions.